This invention relates to oscillating nozzle sprinklers which are adjustable to select different arcs of coverage with an integrated selectable precipitation rate, flow rate and range of coverage.
In U.S. Pat. Nos. 4,867,378 and 4,901,924 sprinklers are disclosed that have adjustable arcs of oscillation and an indicator on the top of the nozzle that displays the selected arc angle. In U.S. Pat. No. 5,417,370 a reversing gear drive with settable arc of oscillation is disclosed. These patents illustrate several drive mechanisms for oscillating sprinklers in which the arc-of-coverage is easily adjustable, and which provide an indication of the selected arc angle on the top of the nozzle. Other types of drive mechanisms such as ball drives and reversing turbine gear drives can also be used in such sprinklers.
In U.S. Pat. No. 5,098,021 an oscillating nozzle sprinkler with integrated adjustability of both arc of coverage and flow is disclosed. In this patent, the selected flow rate (or the corresponding precipitation rate) is displayed on the top of the nozzle separately from the selected arc setting. This patent also discloses a nozzle configuration with an adjustable throat plug for changing the flow rate through the nozzle and various configuration for providing different water distribution patterns.
In U.S. Pat. No. 5,086,977, an oscillating water driven sprinkler is disclosed having a nozzle in which the stream elevation angle or spray range is adjustable from the top surface of the nozzle using a screw mechanism.
In U.S. Pat. No. 6,237,862, a nozzle configuration is shown in which the nozzle tube is surrounded by and attached to a flexible thin diaphragm. The shape of the diaphragm allows the nozzle tube to be effectively hinged so that deflecting the nozzle tube establishes a desired sprinkler steam exit angle.
Above-mentioned U.S. Pat. Nos. 4,867,378, 4,901,924, 5,417,370, 5,098,021, and 6,237,862 provide general, technical background, and further physical and mechanical background for the features and improvements of this invention, and are incorporated by reference herein as if fully disclosed.
None of these patents, however, nor any other sprinklers known to applicant, provide the capability for automatic adjustment of the flow to maintain a preset precipitation rate as the spray range and/or arc of coverage is adjusted. In some instances, stream break-up screws have been provided, but there has been no way to maintain a constant precipitation rate if a pre-selected spray range or arc of coverage was changed in the field, or even to know how the precipitation rate was affected by such changes without performing a laborious calculation from catch cup data, which was rarely done in practice.
The installer may need to adjust the ranges and arc angles of some or all of the sprinklers at the time of installation. Since it is important that the precipitation rates of individual sprinklers or groups of sprinklers be known and matched for uniform precipitation, and the flow for a given precipitation rate varies with the spray range and arc angle, nozzles of different flow rates and for different rangess of coverage must be available. It has thus been customary to install different nozzles at different locations in complex layouts in order to achieve reasonably uniform precipitation.
A need clearly exists for a sprinkler in which the arc angle, spray range, and precipitation rate are adjustable, and in which a desired precipitation rate can be set and maintained by automatic changes in the flow rate as adjustments of the arc angle and spray range are made by the user.
It is accordingly an object of this invention to provide an oscillating nozzle sprinkler in which the arc angle and precipitation rate are adjustable, and in which a desired precipitation rate can be set and maintained by automatic changes in the flow rate as adjustments of the arc angle are made by the user.
It is also an object of this invention to provide an oscillating nozzle sprinkler in which the spray range and precipitation rate are adjustable, and in which a desired precipitation rate can be set and maintained by automatic changes in the flow rate as adjustments of the spray range are made by the user.
It is a further object of this invention to provide an oscillating nozzle sprinkler in which the arc angle, spray range, and precipitation rate are adjustable, and in which a desired precipitation rate can be set and maintained by automatic changes in the flow rate as adjustments of the arc angle and spray range are made by the user.
It is an object of this invention to provide oscillating nozzle sprinklers as described above in which adjustments can be made from the top of the nozzle.
It is a related object of this invention to provide oscillating nozzle sprinklers as described above in which indicators are provided on the top of the nozzle to show the selected settings for the arc angle, the spray range and the precipitation rate.
These objects are achieved by coupling an adjustable flow control mechanism to separate independently adjustable spray range and arc control mechanisms. Rotatable members representing each of these functions are provided on the top of the sprinkler nozzle housing so that they may be set relative to each other on a precipitation rate scale located between the rotatable members.
Now the flow rate can be set relative to the arc and to the maximum spray range to provide a desired precipitation rate, and if the arc angle is increased or decreased, the flow automatically increases or decreases to compensate for the change and to maintain the preset relative precipitation rate. Similarly, if the spray range is reduced from its maximum value, the flow is correspondingly decreases so that, again, the precipitation rate does not change.
Thus, with the sprinkler according to this invention, a preset relative known precipitation rate can be maintained for all arc settings and ranges of coverage, and complex calculations and field adjustments of flow rate can be avoided.
The indication on the top of the sprinkler will allow all of the sprinklers used in a particular irrigation zone which all run at the same time at approximately the same pressure to be correctly set relative to each other. While the exact numbers as indicated will vary as the square root of the pressure from that of the sprinkler""s design normal pressure. However, these differences are small unless pressure is greatly different from design and the sprinklers will all be performing relative to each other for that irrigation zone where they are all turned on and off together.
Different scales can even be provided for high pressure or low pressure sprinklers.
Likewise, the installer can set sprinklers operating in groups relative to each other for the same precipitation (matched precipitation) which is what is most important and sprinklers whose range must be shortened will then flow the correct amount of water without having to change nozzles.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.